The thermal decomposition behaviors of four chemically modified polyethylene were investigated by high resolution pyrolysis gas chromatography|mass spectrometry (HR PyGC-MS).The results revealed that substituents attached to maleated polyethylene as amides formed from secondary amines are significantly less stable than imides formed from primary amines.N-methylaniline amide-derivatives of maleated polyethylene undergo significant decomposition at 160℃ and substantial decomposition at 200℃.In contrast,the imides (except aniline imide) derivatives of maleated polyethylene are stable for long periods of time at 160℃,and the decomposition of phenethylamine imide-,9-aminomethylphenanthrene imide-derivatives is initiated slowly at 255℃ and 280℃,respectively.The effect of different modified groups on thermal stability of the polymers was discussed based on the qualitative and quantitative determination of the products.The thermal degradation pathways for the above chemically modified polyethylene were suggested. The thermal decomposition behaviors of four chemically modified polyethylene were investigated by high resolution pyrolysis gas chromatography | mass spectrometry (HR PyGC-MS). The results revealed that the attached attached to maleated polyethylene as amides formed from secondary amines are significantly less stable than imides formed from primary amines. N-methylaniline amide-derivatives of maleated polyethylene just significant decomposition at 160 ° C and substantial decomposition at 200 ° C. In contrast, the imides (except aniline imide) derivatives of maleated polyethylene are stable for long periods of time at 160 ° C, and the decomposition of phenethylamine imide-, 9-aminomethylphenanthrene imide-derivatives is initiated slowly at 255 ° C and 280 ° C, respectively. The effect of different modified groups on thermal stability of the polymers was discussed based on the qualitative and quantitative determination of the products. the thermal degradation pathways for the above chemically modif ied polyethylene were suggested.